Sensing danger, you fling yourself away from your assailant.

You instantly move 10 ft. in a straight line. At the end of this movement, you cannot be closer to the creature than you started. Opportunity attacks have disadvantage against you if they are triggered by this movement. If you take damage while moving in this way, by an opportunity attack or otherwise, you fall prone at your destination.

If an object in your path blocks your movement, you fall prone in front of it. If there is a creature in your path, it makes a Strength saving throw. On a success, it stops you in your tracks and knocks you prone. On a failure, it is shoved into an unoccupied space. It automatically succeeds if it is two or more size categories larger than you, and it automatically fails if it is two or more size categories smaller.

The distance you can launch yourself increases by 5 ft. when you reach 5th level (15 ft.), 11th level (20 ft.), and 17th level (25 ft.). You do not have to move the maximum distance, though the minimum distance is 10 ft.